CodeListing 1: Explain plan report on BIG TABLE query

 
Id       Operation           Name        Rows    Bytes  TempSpc  Cost    (%CPU)

 0     SELECT STATEMENT                  1833K    85M            21993    (6)
 1     SORT GROUP BY                     1833K    85M    225M    21993    (6)
 2     TABLE ACCESS FULL     BIG_TABLE   1833K    85M             2417    (12)